The present invention relates to a seat in general, and more particularly to an adjustable seat for use in motor vehicles. Even more particularly, the present invention relates to an arresting arrangement which blocks the seat in a multitude of adjusted positions.
Many constructions of adjustable seats for motor vehicles are already known and in widespread use. Among others, there is also already known a construction of the adjustable seat wherein the seat proper is mounted, at each of its sides, on a guiding arrangement which consists of a front guide track and a rear guide track each of which has different inclination with respect to the horizontal. Support elements contact the guide tracks of the two guiding arrangements and thus support the seat proper on the respective guide tracks for displacement longitudinally thereof and thus frontwardly or rearwardly relative to the motor vehicle in which the adjustable seat and the guiding arrangements thereof are mounted. It is also already known to arrange an arresting mechanism in the region of at least one of the guide tracks, the arresting mechanism serving to block the seat proper in a plurality of adjusted positions.
An adjustable seat of this construction is known, for instance, from the German Pat. No. 766,073, wherein the rear guide track of each of the guiding arrangements encloses a larger acute angle with the horizontal than the front guide track. The seat is equipped with a rotatable roller for each of the guide tracks, the respective roller being in a rolling contact with the respective associated guide track and thus supporting the seat on the latter for displacement longitudinally thereof. The two rollers which are arranged at the front region of the seat are mounted on hollow axles, and spring-biased arresting bolts are displaceably mounted in the hollow axles. In its arresting position, each of the arresting bolts extends into an opening of a row of openings which is provided in the support of each of the guide tracks arranged at the front region of the seat. The arresting bolts can be brought out of engagement by links or ropes actuated by a hand-operated lever so that the seat of the motor vehicle can be displaced on the guide tracks subsequent to such a release. Because of the inclination of the guide tracks, the longitudinal displacement of the seat is accompanied by an adjustment of its elevation as well as an adjustment of its inclination.
This conventional arrangement is disadvantageous in many respects. First of all, the guide tracks are relatively short so that only a small adjustment range of the seat can be utilized. Moreover, the seat can only be arrested in a limited number of adjusted positions, the number corresponding to the number of the above-mentioned openings of the row of openings, and at spacings corresponding to the distances of the openings from one another. Inasmuch as these distances of the openings are predetermined by the dimensions of the arresting bolts which, in turn, are determined by the calculations of static requirements, on the one hand, and by the cross-sections of the supports for the guide tracks, on the other hand, a fine adjustment of the seat in each desired seat position is impossible. In addition thereto, it is very difficult if not impossible with this arresting arrangement to arrest the seat in a desired position, particularly when the adjustment of the seat position is accomplished rapidly.